What does "chafing" mean?

Chafing: The act of rubbing, or wearing by friction; making by rubbing. Chafing dish, a dish or vessel for cooking on the table, or for keeping food warm, either by coals, by a lamp, or by hot water; a portable grate for coals. -- Chafing gear (Naut.), any material used to protect sails, rigging, or the like, at points where they are exposed to friction.